Automatic feed for cable-tool drills



June 11, 1957 -r. o. DAVIDSON 2,795,396

AUTOMATIC FEED FOR CABLE-TOOL DRILLS Filed April' 5, 1951 6 Sheets-Sheet J 20 I, 2\ '11: 1; :11, i \\I\ I I 2 I l 1/ 5 l I 28 1 E a 3: 5o

2e 46 25 E A I FIG. 2

TREVOR O. DAVIDSON,

ATTORNEY.

June 11, 1957 -r. o. DAVIDSON 2,795,396

AUTOMATIC FEED FOR CABLE-TOOL DRILL-S Filed April 5, 1951 6 SheetsSheet 2 TREVOR O. DAVIDSON, IN V EN TOR.

WW/W1 ATTORNEY June 11, 1957 'r. o. DAVIDSON 2,

AUTOMATIC FEED FOR CABLE-TOOL DRILPS Filed April 5, 1951 6 Shets-Sheet :s

FIG.4

TREVOR o. DAVlDSON,

INVENTOR.

ATTORN EY June 11, 1957 1: o. mvmson AUTOMATIC FEED FOR CABLE-TOOL. DRILLS.

.6 Sheets-Sheet 4 Filed April 5, 1951 TREVOR O. DAVIDSON,

I l V 25a.

7 v o M u INVENTOR. \o7-- 2%- BY U l CZ?) HP v ATTORNEY. Y

June 11, 1957 T. o. DAVIDSON 2,795,395

AUTOMATIC FEED FOR CABLE-TOOL DRILLS Filed April 5, 1951 6 Sheets-Sheet 5 TREVOR O. DAWDSON) INVENTOR.

WWW

ATTORNEY.

. June 1957 T. o. DAVIDSON 2,795,396

AUTOMATIC FEED FOR CABLE-TOOL: DRILLS Filed April 5, 1951 v s Sheets-Sheet 6 FIG. INVENTOR.

7o TREVOR o. DAWDSON.

United States Patent AUTOMATIC FEED FOR CABLE-TOOL DRILLS Trevor 0. Davidson, Milwaukee, Wis., assignor to Bucyrus-Erie Company, South Milwaukee, Wis., a corporation of Delaware Application April 5, 1951, Serial No. 219,481

9 Claims. (Cl. 255--15) This invention relates to new and useful improvements in automatic feeds for cable-tool drills. Such drills, per so, are well known. For purposes of illustration, the invention is shown used with cable-tool drills of the spudding-beam and pneumatic types, but it is to be understood that the invention is not to be limited to drills of these two types, nor to any particular variety of either type.

In spudding beam drills of the variety shown and described herein for illustrative purposes, a rope or line passes from a winch drum on the main frame, around a heel sheave at or near the pivot of the spudding beam, thence around a sheave at the oscillating end of the spudding beam, thence over a resiliently-supported crown sheave at the upper end of the mast and thence vertically downward into the hole which is being drilled in the ground. At the lower end of this rope is a string of percussion drilling tools, terminating in a bit. The spudding beam is oscillated by a pitman, which in turn is actuated by a rotating crank.

-In pneumatic drills of the variety shown and described herein for illustrative purposes, the rope or line passes from the winch drum, around a sheave at or near the rear end of the machine, thence under another sheave at or near the front end of the machine, behind the foot of the mast, thence over the crown sheave near the upper end of the mast, and thence downward into the hole which is being drilled in the ground. Either the crown sheave or the sheave at the front of the machine is resiliently supported. The drill tools are reciprocated up and down by oscillation of the crown sheave, which is slidably mounted in the mast and actuated by a pneumatic cylinder-piston assembly.

As the hole grows deeper, the winch drum must unwind to pay out more rope. It is the principal object of this invention to devise a new type of feed which will pay out additional rope automatically and smoothly, when and as needed, and unaffected by variable conditions such as atmosphere and lubrication.

Another principal object of this invention is to provide an automatic feed in which the paying-out of rope is effected indirectly by compression of the resilient support, the compression arising from the fact that the hole has reached a depth greater than the reach of the cable payed out from the drum at the particular time. Compression of the resilient support beyond a pre-set amount actuates a unique paying-out mechanism which positively rotates the winch drum a predetermined amount to pay out rope.

In addition to the principal objects above stated, a number of novel and useful details have been worked out, which will be readily evident as the description progresses.

The invention consists in the novel parts and in the combination and arrangement thereof, which are defined in the appended claims, and of which four embodiments are exemplified in the accompanying drawings, which are hereinafter particularly described and explained.

ICC

Throughout the description the same reference number is applied to the same member or to similar members.

Figure 1 is a side elevation of a spudding-beam drill equipped with the first embodiment of the invention.

Figure 2 is an enlarged side elevation of the mast head of the drill shown generally in Figure 1.

Figure 3 is an enlarged top View, partly in cross-section, of a portion of the main machinery of the drill shown generally in Figure 1.

Figure 4 is an enlarged top view, partly in cross section, of a second embodiment of the invention.

Figure 5 is a side elevation, partly cut away, of a pneumatic-type drill equipped with a third embodiment of the invention.

Figure 6 is an enlarged side elevation, partly in crosssection, of a portion of the main machinery of the drill shown generally in Figure 5.

Figure 7 is an enlarged side elevation, partly in crosssection, of a fourth embodiment of the invention.

Figure -8 is a plan view of a portion of Figure 1, taken along the line 8--8 of Figure 1.

Figure 9 is a schematic electric wiring diagram showing the details of and operating connections between contactor switches 27 and 70 and solenoid valve 66.

Turning now to Figure 1, it is seen that 11 is the main frame of a spudding drill, supported by creeping traction 12.

The frame 11 supports a mast 13, a motor 14, a winch 15, a spudding gear or crank 16, and associated driving connections, not numbered. Spudding beam 17 is oscillated by rotation of spudding gear 16 through pitman 18, and is pivoted on horizontal pivots 19 on the frame 11. This mechanism is well known in the art and constitutes no part of the present invention, and consequently need not be detailed here.

Crown sheave 20, near the top of mast 13, is mounted in housing 21, which is arranged in any convenient manner to slide up and down with respect to the mas-t. This housing rests upon resilient support 22, which may be of the type shown in U. S. Patent No. 1,750,826 granted March 18, 1930, to George R. Watson. Any alternative support would be satisfactory for the purposes of this present invention, provided it compresses with each stroke of the tools and then expands again. Sheave 20, housing 21, and support 22 thus collectively constitute a yieldable member, support-ing rope or line 23.

Rope 23 passes from winch 15 around heel sheave 24, under spudding sheave 25, over crown sheave 20 and thence down to the tools 26.

Spudding gear 16 is at will clutched to, and unclutched from, the motor 14, through a clutch and intermediate gearing (not shown) of any convenient sort, all of which is well known in the art and need not be detailed here since the control of the spudding means has nothing to do with the winch and hence constitutes no part of the present invention. Also carried by frame 11 is an airpump (not shown) powered by motor 14, and an air tank 72 for storing air under pressure.

The foregoing description of the spudding means has been given for clearness of understanding only, and no unnecessary limitation should be understood therefrom.

Turning now to Figure 2, it is seen that mast 13 carries a normally-open contactor 27, which is a well-known commercial article, and hence will not be shown in detail. The housing 21 carries a cooperating actuator 28, the position of which is adjustable by set-screw 29, or in any other convenient manner. This actuator 28 is to be so adjusted that it will actuate the button 30 of the contactor 27 whenever the dropping of tools 26 compresses resilient support 22 to a predetermined extent,

.i. e., more than the optimum for percussion drilling. This occurs whenever, due to the drilling, the bottom of the hole recedes sutliciently so that the bit no longer makes proper impact against the bot-tom of the hole.

Turning now to Figures 1 and 8, it is seen that winch 7.5 includes rope drum 31 mounted to rotate with shaft 32, which is operatively connected to motor 14 through drive belt 14a, gears 14b, 14c, 14d and 142, and clutch 14;. These details are conventional and form no part of my invention.

Turning now to Figure 3, it is seen that gear 33 is keyed to shaft 32 and meshes with gear 34, which in turn meshes with and is driven by pinion keyed to shaft 36. Gears 33, 34 and 35 are mounted in and are protected by housing 37.

Still referring to Figure 3, it will be seen that winch drum 31 is also drivably connected to a second motor in the form of a cylinder-piston assembly, which consists of a hollow cylinder 38 closed at one end by cylinder head 39, and containing piston 41. Piston 41 is longitudinally movable within cylinder 38, but is keyed to the cylinder by means of keys 42 to prevent rotation within cylinder 38. Cylinder 38 is mounted on housing 43 by means of studs 44. Housing 43 is supported by frame 11 (Figure 1).

Mounted on piston 41 by means of studs 45 is one half 4641 of a jaw clutch 46. The other half 46b of this clutch is carried by internally-threaded nut 47 rotatably mounted on control screw 48. Also attached to piston 41, by means of studs 49, is a piston follower ring 50. Mounted on ring 50 between the ring and the back of nut 47 is a thrust bearing 73. Piston 41 is normally restrained to the position shown in Figure 3 by means of compression spring 51 acting against follower ring 50.

Control screw 48 is keyed to shaft 36 to which is similarly keyed pinion 35 and a brake disc 52. Compression spring 53 is mounted on rotatable cap 54, which in turn is mounted for rotation with thrust hearing 55 based against housing 56. Compression spring 53 acts against plate 57 on the end of shaft 36.

An internal portion of housing 71 is milled to serve as a stationary disc 58. Friction disc 59is mounted between brake disc 52 and stationary disc 58. It will be seen that spring 53 exerts a force pressing friction disc 59 between discs 52 and 58, thus creating a braking force which normally prevents rotation of shaft 36.

Control lever 60, pivotally mounted in housing 56 by means of bearing 61, has at its lower end fingers 62 which fit within groove 63 of collar 64. Collar 64 is fixed to shaft 36.. Shaft 36 is mounted in straight roller bearings 65, so that it is free to move longitudinally as well as to rotate.

In the normal position shown in Figure 3, the two halves 46a and 46b of jaw clntch 46 are separated (out of engagement) by a distance approximately equal to the thickness of friction disc 59. Thus, even when disc 59 has worn down to the minimum thickness, with spring 53 compensating for this wear by shifting shaft 36 longitudinally to the right, jaw clutch 46 will in the normal position still be out of engagement.

The operation of the embodiment of this invention shown in Figures 1 to 3 is as follows.

The closing of normally-open contactor 27 by actuator 28 (both of which were described in connection with Figure 2) energizes a solenoid valve 66 (Figures 1 and 9) in such a manner as to open the valve to permit flow of air under pressure from tank 72. This valve is a well-known commercial article and need not be shown in detail, since it forms no part of this invention. When energized this valve remains open until other means act to close it, as will be explained below.

The opening of valve 66 permits air under pressure to flow from air-pressure tank 72 through line 74 to valve 66 and thence through line 67 and passage 68 into cylinder 38. The pressure in cylinder 38 forces piston 41 to move to the left, as seen in Figure 3. The initial move ment of piston 41 causes engagement of clutch 46; thereafter, thrust from piston 41 is transmitted to nut 47 and thence to control screw 48 and shaft 36 as thrust and also as torque, since nut 47 is held against rotation by the engagement of clutch 46, which is connected to non'rotatable piston 41.

The thrust load thus imposed acts against spring 53, reducing the braking force on brake disc 52. As the thrust increases, the torque transmitted to shaft 36 increases, and the load on brake disc 52 decreases, with a corresponding decrease in brake holding force.

When the thrust imposed on screw 48 increases to thc point where the resulting torque imposed on the screw and on shaft 36 exceeds the diminishing brake holding force, shaft 36 will rotate, control screw 48 and pinion 35 of course rotating with the shaft. During this rotation, nut 47 moves to the left, which movement continues as long as piston 41 is forced to the left by a pressure sutficient to keep disc 52 unbraked.

As long as jaw clutch 46 is engaged nut 47 cannot rotate, so that axial movement of nut 47 causes pinion 35 to rotate. This rotation of pinion 35, through the 7 intermediate action of gears 34 and 33, causes the rotation of shaft 32 and drum 31 in a direction to pay out rope 23.

If, during the functioning of the invention as described above, rope 23 should exert an excessive pull on drum 31, thereby causing the drum to overspeed pinion 35 on follower ring 50 contacts control switch 70, which is similar to contactor 27 (Figure 2). This actuation of switch 70, by means of an electrical connection (Fig ure 9) with solenoid valve 66, shuts valve 66 to cut oil the flow of air from tank 72 to cylinder 38 and opens another passage through valve 66 to permit the air in cylinder 38 to exhaust through passage 68, line 67 and port 75 of valve 66 to the atmosphere. When the pressure of the air in cylinder 38 has thus dropped sufficient- 1y, spring 51 returns piston 41 to its original position (Figure 3). Initial return movement of the piston permits spring 53 to reset brake 52, 59, 58, and then disengages clutch 46; this leaves nut 47 free to rotate on screw 48 so that with subsequent return movement of piston 41 piston follower ring 50 carries nut 47 back to its original position.

The position of control switch 70 is adjustable to the right or left (Figure 3') by any convenient means (not shown). Moving switch 70 to the right reduces the travel of piston 41 and nut 47, thus reducing the feed of rope 23 for a particular impulse from contactor 27 (Figure 2). Moving switch 70 to the left increases the feed.

Although not necessary to the invention, the embodiment shown in Figure 3 has cylinder 38 and housings 37, 43, 71 and 56 interconnected. When so constructed, the unit can carry sufficient oil to lubricate all parts of the mechanism.

When the machine operator wishes to let the tools down into the hole manually, he moves lever 60 to the right. Fingers 62 at the lower end of lever 60 force collar 64, and with it shaft 36, brake disc 52, and piston 41, to'the left, thus releasing brake 52, 59, 58 and permitting shaft 36 and drum 31 to rotate under the influence of the weight of the tools 26, nut 47 rotating with screw 48 and shaft 36. Since in the normal position shown in Figure 3, cylinder 38 is vented to the atmosphere through valve 66, this movement to the left of shaft 36 and piston 41 is not hindered by the building-up of a vacuum in cylinder 38. Due to the presence of bearing 73, the non-rotatability of piston 41 does not hinder rotation of nut 47.

When the operator wishes to raise the tools, he releases brake 52, 59, 58 as described above, and simultaneously clutches drum 31 to motor 14 by the clutching means 14 (Figure 8), which may be interconnected in a conventional manner to lever 60 to release brake 52, 59, 58 whenever the clutching means is engaged, but without interference with the independent release of the brake to lower the tools.

The second embodiment of this invention is shown in Figure 4. The cylinder-piston assembly and immediately associated parts, and their operation, are the same as shown in Figure 3, except that brake-release means 60, 61, 62, 63, 64 is eliminated, the function of this means being otherwise performed, as will be seen from the following description; consequently, the main part of the assembly is not again shown in detail. Keyed to shaft 32a, which is mounted for rotation on frame 11 (Figure 1), are gear 33 and pinion 80. The winch drum 31a is nowv rotatably mounted on the shaft 32a instead of being keyed to the shaft as in the case of the first embodiment shown in Figure 3. Gear 33 meshes with gear 34, which in turn meshes with and is driven by pinion 35 on shaft 36, as previously described in connection with Figure 3. Winch-drum 31a carries with it stub shafts 81 upon which planet gears 82 are rotatably mounted. Planet gears 82 mesh with pinion 80, which functions as the sun gear of a planetary-gearing system, and also with internal teeth 83 of ring gear 84. Ring gear 84 also has external gear teeth 85, and through this means and other conventional means not shown, gear 84 may at will be clutched to motor 14 (Figure l).

Milled about a portion of the periphery of ring gear 84 is a brake facing 86, which cooperates with brake band 87 mounted on frame 11 (Figure 1). Brake 86, 87 normally acts to restrain ring gear 84 from rotation, but may be released by the drill-operator at will by conventional means not shown. I

The operation of the second embodiment of the invention is as follows. Brake 52, 5'9, 58 (see Figure 3), through the connection consisting of shaft 36, pinion 35, gears 34 and 33 and shaft 32a, normally holds sun gear 80 from rotation. Since brake 86, 87 normally holds ring gear 84 from rotation, planet gears 82 are restrained from movement and drum 31a is thus held stationary to prevent paying out or winding in rope 23.

When, as explained in connection with the description of Figure 3, the actuation of the cylinder-piston assembly forces rotation of pinion 35 (in a counterclockwise direction as viewed from the right of Figure 4), gear 34 is rotated in a clockwise direction. This rotates gear 33, shaft 32a and sun gear 80 in a counterclockwise direction, and since ring gear 84 is held fast, planet gears 82 will be rotated clockwise about their shafts 81 and will be carried in a counterclockwise direction about shaft 32a. This last movement rotates drum 31a to pay out rope 23.

When the operator wishes to let the tools down into the hole manually, he releases brake 86, 87, freeing ring gear 84 for rotation. Brake 52, 59, 58 (Figure 3) restrains sun gear 80. The weight of the tools (Figure 1) on rope 23 then forces drum 31a to rotate counterclockwise, carrying planet gears 82 along. The planet gears rotate about shafts 81 and also rotate as planets about shaft 32a. Rotation of the planet gear forces counterclockwise rotation of ring gear 84.

- When the operator wishes to raise the tools, he releases brake 86, 87 and simultaneously clutches ring gear 84 to motor 14 by the clutching means (not shown), which may be interconnected in a conventional manner to the brake release means to release brake 86, 87 whenever the clutching means is engaged, but without interference with the independent release of the brake to lower the tools. Clutching ring gear 84 to motor 14 causes clockwise rotation of the ring gear, and, since brake 52, 59, 58 (Figure 3) restrains sun gear 80 from rotation, the ring gear will force planet gears 82 to rotate about the sun gear in a clockwise direction. This rotation of the planet gears carries winch 31a along, thus winding in rope 23.

The third embodiment of the invention, shown here mounted on a pneumatic-type drill, is illustrated in Figures 5 and 6.

Turning firstto Figure 5, it is seen that 11 is the main frame of a pneumatic drill, supported by creeping tractor 12.

Frame 11 supports a mast 13, a motor 14, a winch 15, an air pump 99 and an air tank 72 for storing air under pressure.

Crown sheave 20, near the top of mast 13, is mounted for rotation at the upper end of a piston rod 100 which is supported within mast 13. Piston rod 100 is reciprocated up and down by a conventional air-operated singleacting cylinder-piston assembly 101, mounted at the base of mast 13. Assembly 101 is fed with air by means of lines, valves and controls of conventional type which are not shown here since they are well known in the art and form no part of the invention; and together with piston rod- 100 and crown sheave 20, constitutes the spudding means of this drill.

Rope 23 passes from winch 15 around heel sheave 24, under front sheave 102, over crown sheave 20 and thence down to the tools 26.

Front sheave 102 is mounted in a housing 103 which is supported by a restraining member 104 connected to frame 11. Mounted between housing -103 and member 104 is a resilient support 22, similar to that described in connection with Figure l. Sheave 102, housing 103, member 104 and support 22 thus constitute a yieldable member engaging rope 23.

The foregoing description of the main machinery of the drill has been given for clearness of understanding only, and no unnecessary limitation should be understood therefrom.

Still referring to Figure 5, it is seen that member 104 carries a normally-open contractor 27a, which cooperates with an actuator 28a on housing 103. This is similar to the arrangement described in connection with Figure 2. The actuator 28a is to be so adjusted, by a set-screw or other well-known means, that it will actuate the contactor 27a whenever the dropping of tools 26 compresses resilient support 22 to a predetermined extent, i. e., more than the optimum for percussion drilling. This occurs whenever, due to the drilling, the bottom of the hole recedes sufficiently so that the bit no longer makes proper impact against the bottom of the hole.

Contactor 27a is operatively connected to solenoid valve 66 by electrical means 105. Whenever contactor 27a is actuated by actuator 28a, solenoid valve 66 opens to admit air under pressure to air-actuated single-acting cylinder-piston assembly 106. This pressure air is carried to valve 66 from tank 72 by lines (not shown), and when valve 66 opens, the air passes into assembly 106 through line 107. I

Figure 6 shows an enlarged side elevation, partly in cross-section and partly cut away, of the third embodiment of the invention. Keyed to shaft 32, on which winch drum 31 is mounted, is ratchet gear 108. Mounted for rotation on shaft 32, and positioned outside gear 108, is lever 109, at the outer end of which a pawl 110 is pivotally mounted. Pawl 110 has three arms 141, 142 and 143. Pivotally attached to arm 141 of pawl 110 is the external end of piston rod 112.

The. periphery of winch-drum 31 is milled to serve as a brake drum 113, brake band 114 being mounted to cooperate with drum 113. The dead-end of band 114 is pivoted to bracket 115 on frame 11. The live-end of band 114 is pivotally attached to the upper end of a bell-crank 116, which is pivoted at 117 intermediate its ends for rotation on bracket 118 on frame 11. Brake lever 119 is fixed to bell-crank 116 adjacent pivot 117. Link 120 is pivotally attached to the lower end of bellcrank 116', and to the lower end of a second bell-crank 121, the upper end of which is pivotally connected to bracket 122 on frame 11.

Pivotall-y mounted on bell-crank 12'1 intermediate its ends is cylinder-piston assembly 106 which includes cylinder 123, piston 124, piston rod 112 and compression spring 125.

Rigidly mounted on horizontal transverse frame memher 126 (shown here in cross-section) is a member 127, having a lower arm 128 and a side arm 129. Lower'arrn 123 has a stop 130 arranged to contact the lower arm 142 of pawl 110 just prior to the time the mechanism reaches the normal (inactive) position shown in Figure 6. Side arm 129 has adjustably mounted thereon an electrical contactor 2712 similar to contactor 27 described in connection with Figure 2. Contactor 27b is arranged to contact arm 141 of pawl 110 when the pawl has been carried around on lever 109 to the position at which contactor 27b has been set. Contactor 27b is operatively connected to valve 66 by electrical means (not shown) in such a way that whenever actuated it shuts valve 66 to cut off flow of air from tank 72 to cylinder 123 and opens another passage through valve 66 to permit the air in cylinder 123 to exhaust to the atmosphere.

Tension spring 133 is connected between lever 109 and cylinder 123 to bias lever 109 normally in the position shown.

The operation of this third embodiment of the inven tion is as follows:

As previously described, the actuation of solenoid valve 66 resulting from compression of resilient support 22 opens the valve to permit pressure air from tank 72 (Figure to flow into cylinder 123 (Figure 6). The force from this pressure air against piston 124 forces piston rod 112 out of cylinder 123, compressing spring 125, and extending spring 133.

The initial movement of piston rod 112 forces pawl 116 to rotate in a counterclockwise direction about its pivot on lever 109, at the same time rotating lever 109 slightly in the same direction about its pivot on shaft 32. This rotation forces arm 143 of pawl 110 into contact with one of the teeth of ratchet gear 108.

Further movement of piston rod 112 exerts a force on gear 108 tending to rotate shaft 32 and winch drum 31 in a counterclockwise direction to pay out rope 23. This rotation is opposed by the restraining force of brake band 114 on brake drum 113, and since the rotation is toward the live end of the brake band, this opposing force is of considerable magnitude. To overcome this force would require a large cylinder-piston assembly '106 and/ or very high air pressure, both of which for obvious reasons are to be avoided if possible. This problem is solved by mounting cylinder-piston assembly 106 on bell-crank 121, to which the live end of brake band 114 is connected by means of link 120 and bell-crank 116. Then the reaction of the force tending to expel piston rod 112 from cylinder 123 also exerts a force tending to rotate bell-crank 121 in a counterclockwise direction about its pivot on bracket 122, and this rotational force exerts a pull on link 120, which in turn exerts a force tending to rotate bell-crank 116 in a counterclockwise direction about its pivot 117 on bracket 118, brake lever 119 being sutiiciently flexible to permit of such a limited rotation. Rotational movement thus initiated releases brake band 114 so that rotation of drum 31 is possible with a minimum of applied force.

As gear 108 is forced to rotate to pay out rope 23, lever 109 continues to rotate about shaft 32 against the opposing force of spring 133, carrying with it pawl 110. After a predetermined amount of this rotation, dependent upon the position of contactor 27b on side arm 129, arm 141 or pawl 110 contacts the contactor 27b, cutting off the flow of air into cylinder 123 and opening valve 66 to exhaust the cylinder to the atmosphere, as previously described.

As this exhaust occurs, spring 125 returns piston 124 and piston rod 112 to the original position shown in Figure 6, rod 112 carrying with it pawl 110, and together with spring 133 returning lever 109 to the same position. As pawl nears the original position, projection contacts arm 142 of the pawl, thereby forcing the pawl to rotate in a clockwise direction about its pivot on lever 109 so that arm 143 of the pawl is lifted out of contact with ratchet gear 108.

Mounted on upright frame member 134 is a plate 135 having a number of notches cut in its edge. The placement and retention of the forward portion of brake lever 119 under one of these notches causes this lever (through the cooperation of bell-crank 116 and brake-band 114) to exert a braking force on brake-drum 113. The amount of this braking force increases as the lever 119 is placed in successively lower notches in plate 135. Raising brake lever 119 releases the brake for rapid unspooling of winch drum 31 under influence of the weight of the tools 26 on rope 23, or when it is desired to clutch winch 15 to motor 14 to reel in the rope.

The fourth embodiment of the invention is illustrated in Figure 7.

Pivotally attached to arm 141 of pawl 110 is one end of a rod 150, which is externally threaded adjacent its other end, as at 151. Pivotally attached to bell-crank 121, intermediate the ends thereof, is bracket 152. Mountedon bracket 152 are a gear casing 153, a reversible electric motor 154 and an electrical contactor 27d. Motor 154 drives shaft 155, upon which pinion 156 is fixed, and is connected by wires 157 to a source of electric energy (not shown) and to electrical contactors 27a (Figure 5 27c and 27d. The details of these connections are not shown, as they may be of any conventional type well known in the art. Pinion 156 meshes with a gear 158, which is internally threaded and rotatably mounted on the threaded portion 151 of rod 150. Gear 158 is also contained within gear casing 153, so as to prevent lateral movement relative to the casing. Tension spring 133 is connected at one end to lever 109 and at the other end to gear casing 153.

The operation of the fourth embodiment of the invention will be described as it is used with the pneumatic drill illustrated in Figure 5, which operation is as follows.

The closing of normally-open contactor 27a by actuator 28a (Figure 5) closes an electrical circuit between motor 154 and its source of energy (not shown), thus driving motor 154 and causing rotation of shaft 155 and pinion 156. Rotation of pinion 156 causes an opposite rotation of gear 158, which is in a direction to cause expulsion .of rod from gear case 153. This movement of rod 150 causes engagement of pawl 110 with ratchet gear 108, whereuponfurther movement results in rotation of drum 31 and the unwinding of rope 23, as described in connection with Figure 6.

At the predetermined point of travel, arm 141 of pawl 110 contacts contactor 27c, actuation of which opens the circuit driving motor 154 and simultaneously closes a second electrical circuit between the motor and its source of energy so as to drive motor 154 in the opposite direction. The resultant opposite rotation of shaft 155, through the action of pinion 156 and internally-threaded gear 158, causes retraction of rod 150 toward its initial position shown in Figure 7.

As rod 150 reaches this initial (normal) position, it actuates contactor 27a, which acts to break the circuit driving motor 154.

The retraction of rod 150, together with the action of spring 133 and projection 130 (as explained in connection with Figure 6) returns lever 109 and pawl 110 to their original position (Figure 7).

The mechanism is then in a position to repeat the cycle just described, upon a further actuation of contactor 27a (Figure 5).

From the foregoing description of the four embodiments of the invention, and their operation, it is obvious that each embodiment may be used equally advantageously with either the spudding-beam drill or the pneumatic drill. It is equally obvious that oil or other fluid might be satisfactorily substituted for air as the actuating fluid for the cylinder-piston assemblies in the first three embodiments without departing from the spirit of the invention.

Having now described and illustrated four embodiments of the invention, it is to be understood that the invention is not to be limited to the specific form or arrangement of parts herein described and shown.

I claim: t

1. An automatic feed for a winch-drum, which drum is supported on a base for rotation and is normally held from rotation by a brake, said feed including: a ratchet gear having a driving connection to the winch-drum; a first lever pivotally mounted adjacent one end on the axis of rotation of the ratchet gear, and having pivotally mounted adjacent its other end a pawl which is engageable with the ratchet gear to drive the gear; a second lever pivotally supported by the base and operatively connected to the brake to release the brake when the lever is pivoted in at least one direction; a third lever pivotally supported by the base and operatively connected to the second lever to pivot the second lever to release the brake; and a reversible motor pivotally supported by the third lever and operatively connected to the pawl, to pivot the pawl into engagement with the gear upon initial actuation of the motor and upon further actuation to pivot the second lever to release the brake and force rotation of the ratchet gear and the drum, and to disengage the pawl and reengage the brake when the motor reverses.

2. An automatic feed for a winch which includes: a line, a winch drum normally held from rotation by a brake and operatively connected to the line to wind up and pay out the line, a yieldable member engaging the line, and a load supported by the line; the combination therewith of: a ratchet gear having a driving connection with the drum; a first lever pivoted on the axis of rotation of the ratchet gear; a pawl pivoted on the first lever and engageable with the gear to drive the gear; a second lever operatively connected to the brake to release the brake; extensible-retractible power means; means for pivotally connecting one end of the power means to the pawl; means for pivotally connecting the other end of the power means 7 to the second lever; actuation of said power means successively forcing the pawl to rotate about its pivot on the first lever into driving engagement with the gear, and then releasing the brake and forcing the pawl and the first lever and the gear together to rotate about the pivot axis of the gear to rotate the drum to pay out the line.

3. An automatic feed according to claim 2, characterized by the fact that the combination includes control means, constituting an operative connection between the yieldable member and the extensibleretractible power means, for actuating said power means, in response to the yielding of said member a predetermined amount, to change its length to perform the successive functions listed in claim 2.

4. An automatic feed according to claim 3, further characterized by the fact that the extensible-retractible power means, on being actuated to reverse its change of length, successively sets the brake, and then reversely rotates the pawl about its pivot on the first lever, and then returns the pawland the first lever together to their initial position; and by the fact that the combination includes control means, actuable by a predetermined change of length of the extensible-retractible power means, to actuate said power means to reverse its change of length.

5. An automatic feed according to claim 2, characterized by the fact that the extensible-retractib'le power means comprises a pressure-fluid-actuated cylinder-piston assembly, and that the combination includes: a source of pressure-fluid; valve means, interposed between the source of pressure-fluid and the cylinder-piston assembly for actuating said assembly to rotate the drum to pay out line, and alternatively for shutting ofi pressure-fluid from said assembly and permitting fluid to exhaust therefrom; first control means, constituting an operative connection between the yieldable member and the valve means, for setting the valve means, in response to the yielding of said member a predetermined amount, to admit pressure-fluid to said assembly; and second control means, constituting an operative connection between said assembly and the valve means, for setting the valve means, in response to a predetermined actuation of the motor, to shut off pressure-fluid from the motor and drain the same.

6. An automatic feed according to claim 5, further characterized by the fact that the cylinder-piston assembly includes biasing means to actuate said assembly to succesively set the brake, and then reversely rotate the pawl and the first lever together to their initial position when said assembly is shutoff from pressure fluid and exhausted.

7. In an automatic feed for a normally-braked rotatable drum, the combination therewith of: brake-releasing means; power means, comprising a cylinder-piston assembly; means for operating the power means; an engageable-drive connection between one end of the cylinder-piston assembly and the drum; means actuable by said assembly for sequentially engaging said drive connection and then rotating the drum in an unspooling direction; and brake-release means actuable by the reaction of said assembly when said assembly rotates the drum and operatively connected between the other end of the cylinder-piston assembly and the brake-releasing means for releasing the brake substantially simultaneously when the cylinder-piston assembly rotates the drum.

8. In an automatic feed for a winch which includes: a line, a winch drum normally held from rotation by a brake and operatively connected to the line to wind up and pay out the line; a yieldable member engaging the line; and a load supported by the line; the combination therewith of: a pressure-fluid motor; a source of pressure fluid connected to the motor; a disengageable and engageable drive connection between the motor and the Winch drum, said drive connection being engageable by movement of said motor to pay out the line; means for normally holding said drive connection disengaged; means operatively connecting the brake to the motor and actuable by movement of said motor to release the brake when the drum is driven by said motor to pay out the line; valve means, interposed between the source of pressure-fluid and the motor, for admitting pressure fluid to the motor to actuate the motor to release the brake and to pay out line, and for alternatively shutting off pressure fluid from the motor; first control means, constituting an operative connection between the yieldable member and the valve means, for setting the valve means, in response to the yielding of said member a predetermined amount, to admit pressure fluid to the motor; second control means, constituting an operative connection between the motor and the valve means, for setting the valve means, in response to a predetermined actuation of the motor, to shut ofl pressure fluid from the motor; said motor comprising a pressure fluid actuated valve-controlled cylinder-piston assembly and said disengageable and engageable drive connection comprising a ratchet-type driving connection with the drum, a stroke of said assembly of predetermined length driving said drum to pay out the line a predetermined amount, and said second control means being actuable by further movement of said assembly beyond said predetermined stroke to stop the driving by setting the valve control to cut off pressure fluid from said assembly, and exhaust said assembly; biasing means for thereupon automatically returning said assembly to its original position; and trip means associated with said ratchet connection for automatically disengaging and holding said ratchet disengaged when said assemable drum, the combination therewith of: brake-releasing References Cited in the file of this patent connected between the other end of the motor assembly 10 9,698

and the brake-releasing means for releasing the brake substantially simultaneously when the motor assembly rotates the drum.

UNITED STATES PATENTS Hundhausen Mar. 27, Paschall June 26, Trinkaus July 7, Buschman May 9, Vickers Oct. 7, Meier 2. Mar. 4, Patzer Sept. 9, 

